Marine organisms such as algae, barnacles and teredos or shipworms, do extensive damage to the hulls of boats. The organisms are world wide in distribution and generally live in marine or brackish water although a few species are found in fresh water. They can be extremely destructive to wooden vessels and have been of great concern to maritime people since the earliest times. The ships of Archimedes of Syracuse were protected by a sheathing of lead against the depredations of marine organisms. Copper sheathing was first used by the British in 1758. Although these techniques provided protection to wooden hulls from the toredos, the accumulation of barnacles and algae was not prevented and the sheathing of a boat with such heavy material substantially reduces its mobility. Other techniques to reduce the damage produced by marine organisms has included the use of specialized paints containing a coal-tar cresote solution or paints having a copper base. Fiberglass coatings have also been used to some extent on small boats and a glue used in making marine plywood has been developed which deters marine borers. However, these techniques still do not protect against the accumulation of barnacles and algae.